synchronising data over 3 stations

Hi there!

I have three devices: 2x an arduino with some sensors, transferring data to a laptop each, and the basestation, a third laptop, probably also with an arduino, but not sampling data. The two arduinos with the sensors sample data and display it on a VB application on their laptop. These three devices all move independently from each other.
The goal is now to not only have the own data, but also the data from the other data sampling laptop. And the basestation should have the data of the other two laptops. So three devices should all have the same information. I thought about transmitting data via some XBees, but the hardware part is not the problem.
What I imagine will be the actual problem, is how to synchronise the data without any errors. The stations move and will not always have reception. The amount of data per data sampling laptop is about 3 integers per package (about 10 to 12 digits in total) every 10 seconds, with a total amount of maximum 1000 datapoints, but mostly it will be below 500. The datapoints are not always new, sometimes just an old point gets modified (the first column of the data table stays the same).
I thought about using the basesation as the data managing device, but I would love if it also works only between the two sampling devices.

So how do I manage this constant data juggling and checking if all devices have the same information? Any hint is highly appreciated.

This is more a PC problem than an Arduino problem. There are several doctoral thesis about how to synchronize data between stations that don't have a steady connection.
You don't give enough details about your setup to suggest a solution but if I guess correctly you probably can just connect the 3 laptops by WiFi and send the data to the other two laptops as soon as the data is aquired. If connection interruptions are short enough the TCP/IP protocol stack will handle the interruptions and you don't have to care about. Just ask on a VB forum about how you can transfer data by TCP sockets from one computer to another.